Electrical drives notes by Swaenendu Deb

1. ELECTRICAL DRIVES
NAME – SWARNENDU DEB
ROLL – 27901620023
DEPT. – ELECTRICAL 4TH YEAR

2. TABLE OF CONTENTS
• Introduction
• Block Diagram of Electrical Drive
• Types of Electrical Drives
• Based on Supply
• Based on Number of Motors
• Based on Speed
• Based on Control Parameters

3. TYPES OF DRIVES
In this section, we will briefly review the different types of
variable-speed drives used in industry. For the most part,
electronic AC and DC drives find their dominance in
manufacturing and commercial HVAC applications of
today. This brief look at drive technologies will assist you,
should you encounter any of these types in the future. In
addition, we will also review the benefits and limitations
of each type. The types of drives we will consider are
mechanical, hydraulic, and electrical/electronic (eddy-
current coupling, rotating DC, DC converters, and
variable-frequency AC).

4. BLOCK DIAGRAM OF
ELECTRICAL DRIVE
A modern electrical drive capable of variable controlled speed is made of some important parts as
shown in the below block diagram.

6. BASED ON SUPPLY
Based on Supply
There are two types available in this category. They are
AC Motor drives
AC drive is a device used to control the speed of an electric motor such as a three-phase induction
motor by changing the frequency of the electrical supply to the motor.
AC drive is also called Variable Frequency Drive (VFD) or Variable Speed Drive (VSD).
DC Motor drives
It is basically speed control system of a DC electrical motor that supplies voltage to the motor to
operate at desired speed.
DC drives are classified as analog DC drives and digital DC drives.
Digital DC drive can offer precision control.

7. BASED ON NUMBER OF
MOTORS
There are three types available in this category. They are
Individual
There will be a separate drive motor for various parts of a
machine.
Example: Lathe machine.
Multi Motor
Separate motors are provided for actuating different parts of
a machine.
Example: Cranes.
Group Drive
In a group drive, one motor is used as a drive for two or
several machines.
The motor is connected by a single shaft, other machines are
connected to the shaft by belts and pulleys.
Group drive is most economical.

8. BASED ON SPEED
There are two types available in this category. They are
Constant Speed drive
Machine tools require more or less constant speed drives,
squirrel cage induction motor along with the manual
controls are used.
Variable Speed drive
The main purpose of variable speed drive is to control
speed along with acceleration, deceleration, torque and
finally the direction of machine.
They are used to reduce power consumption.

9. BASED ON CONTROL PARAMETERS
There are three types available in this category. They are
Vector Control Drive
Vector control is most accurate than any other kind of variable frequency drive (VFD).
In this control mode, torque and speed controlled using pulse width modulation (PWM)
techniques in an inverter.
These are used for AC synchronous and induction motors.
Constant Power Drive
When a motor while carrying rated current in its armature provides constant power at all
speeds in a certain range of speed control it is known as constant power drive in that range of
speed control.
Constant Torque Drive
Constant torque load type drive is distinctive when fixed volumes are being handled.
Examples are screw compressors, feeders, and conveyors.

10. THANK YOU…….
ELECTRICAL DRIVES HAVE MANY ADVANTAGES OVER OTHER
MECHANICAL DRIVES. ELECTRICAL DRIVES ARE MORE POPULAR FOR
ITS SIMPLE CONSTRUCTIONS, RELIABILITY, CLEANLINESS, AND SMOOTH
EASY SPEED CONTROL. IN ELECTRICAL DRIVES, BOTH TYPES OF
ELECTRICAL MOTORS, AC AND DC MOTORS ARE USED FOR
APPLICATIONS.